1. Technical Field
The invention relates to an apparatus for the interchangeable connection of a casting tube to a spout of a melt vessel, having a slide closure which is fastened to the melt vessel and is formed by at least one stationary closure plate and a closure plate which is displaceable in relation thereto, wherein the displaceable closure plate is coupled to a displacement drive and bears the casting tube.
2. Prior Art
A slide closure of the generic type is already known, for example, from WO 03/080274. This slide closure is in the form of a two-plate slide, where a movable closure plate can be displaced using a hydraulic actuator between an “open position”, which allows molten metal to pass through, and a “closed position”, which blocks the passage through.
JP 5-318061 discloses a compact subassembly comprising a two-plate slide and a casting tube, which is braced in the operating position by a clamping device and can be released for a joint installation or removal operation.
Slide closures are used, in particular, in continuous casting installations either on the casting ladle or, in particular, on the transfer vessel, in order to ensure a regulated inflow of molten metal into the continuous casting mold and thus a stable casting operation. Refractory closure plate inserts and the casting tubes or shrouds are parts which become worn and often have to be changed. Before the start of the casting operation, the spouts of the melt vessels are closed and have to be opened using special measures. This requires easy and safe manipulation of, for example, a firing device in a hazardous environment for operating personnel.
A series of solutions have already been developed in order to fix a casting tube or shroud firstly in its operating position on the slide closure and to press it onto said slide closure with a specific contact pressure, and secondly in order to be able to change the casting tube.
By way of example, EP 577 909 A1 discloses a mechanism for supporting a casting tube on, and pressing it onto, an outlet of a tundish, wherein the support device comprises a two-arm lever which is pivotable about an external axis of rotation, one end of this lever being provided with a mounting ring for the casting tube and the opposite end being provided with a counterweight for producing a contact pressure on the casting tube. In this design, however, the casting nozzle can be accurately positioned with respect to the outlet opening for the molten metal only by means of an independently displaceable, but therefore dirt-prone, auxiliary nozzle.
U.S. Pat. No. 4,892,235 discloses a support and pressure-exerting apparatus for a casting nozzle, by means of which apparatus the casting tube can be pressed onto a stationary closure plate of a three-plate slide. A fork mount for the casting tube, which can be pivoted in and out about a vertical axis, comprises support bars, which are in the form of spring elements and can be used to produce a substantially predetermined contact pressure after a securing stop has been pivoted in. A series of manipulations have to be carried out manually here to make it possible to change the casting tube, as a result of which the safety of the operating personnel is significantly impaired.
U.S. Pat. No. 4,526,301, EP 891 829 A1, EP 820 825 A1 and AT 349 666 B already disclose changeover devices for casting tubes in conjunction with a three-plate slide, in which the displaceable closure plate is arranged between two stationary closure plates and the casting tube is assigned to one of the stationary closure plates.
Furthermore, the changeover devices described are not suitable for casting tubes and shrouds for use in two-plate slides where the casting tube or shroud is to be fastened to the movable closure plate.